cases 0.2.0

• Added a NEWS.md file to track changes to the package.
• Improved documentation (style, contents) for all functions.
• Added pkgdown site maxwestphal.github.io/cases/
• Bugfixes for several types of analyses that were not utilized (in simulation study) so far, mainly concerned with evaluate arguments analysis="full" and alternative="two.sided".
• Additional unit test have been added.